Heat pumps · Error codes · Alpha Heating Innovation
E183Alpha Heating Innovation · Alpha Hydro 5/8/12/16 R32 monobloc (with Pre-Plumb 200)
E183 on an Alpha Heating Innovation Alpha Hydro 5/8/12/16 R32 monobloc: Outdoor unit in test mode: Condensing unit is in test mode (triggered during outdoor test); heating and DHW requests cannot be met
Short answer
On an Alpha Heating Innovation heat pump, E183 means: Outdoor unit in test mode: Condensing unit is in test mode (triggered during outdoor test); heating and DHW requests cannot be met. The heat pump keeps running with some functions stopped. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Outdoor unit in test mode: Condensing unit is in test mode (triggered during outdoor test); heating and DHW requests cannot be met.
Part involved: test mode.
Likely causes:
- Condensing unit is in test mode (triggered during outdoor test); heating and DHW requests cannot be met.
Is it safe?
| Does the heat pump stop? | Partly |
|---|---|
| Severity | Information only |
| Engineer needed? | Yes |
The heat pump keeps running with some functions stopped.
What you can check
- Note the code and any text shown on the display/controller.
- Check the heat pump isolator and consumer-unit breaker are on.
What the engineer will check
- End outdoor test mode (K1/K2 pressed 3 times).
Who to ask for: heat pump engineer.
Sources
- Alpha Pre-Plumb 200 - Pre-plumbed cylinder with Hydro heat pump - Installation and Servicing Instructions (06-23) ↗ · Pre-Plumb 200 instructions 06-23 · page 37 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026